Cerium oxide nanoparticle functionalized lignin as a nano-biosorbent for efficient phosphate removal

Abstract

Removing excess phosphorus is a highly effective method to prevent eutrophication in contaminated water.However, the design and preparation of an efficient biosorbent for phosphate capture is still a great challenge. We fabricated a novel, and inexpensive nano-biosorbent, L-NH 2 @Ce, by loading cerium oxide nanoparticles (nano-CeO 2 ) within the aminated lignin using a facile in situ precipitation approach for efficient phosphate removal. The as-designed nano-biosorbent L-NH 2 @Ce exhibited a BET surface area (S BET ) of 89.8 m 2 g À1 , 3 times that of lignin, and a pore volume (V p ) of 0.23 cm 3 g À1 . Owing to these results, the adsorption capacity of L-NH 2 @Ce increased by 14-fold to 27.86 mg g À1 compared with lignin (1.92 mg g À1 ). Moreover, the L-NH 2 @Ce can quickly reduce a high phosphate concentration of 10 ppm to well below the discharge standard of 0.5 ppm recommended by the World Health Organization (WHO) for drinking water. Importantly, a study of leaching tests indicated the negligible risk of Ce ion leakage during phosphate adsorption over the wide pH range of 4-9. Moreover, L-NH 2 @Ce exhibits good reusability and retains 90% of removal efficiency after two adsorption-desorption cycles.The environmentally benignity of the raw material, the simple preparation process, and the high stability and reusability makes L-NH 2 @Ce a promising nano-biosorbent for phosphate removal. † Electronic supplementary information (ESI) available: The phosphate adsorption capacity of L-NH 2 @Ce in comparison with some biosorbents. See Fig. 3 (a) Adsorption kinetics of phosphate on L-NH 2 @Ce, and fitting results for (b) pseudo-second-order model and (c) pseudo-first-order model on L-NH 2 @Ce. 1254 | RSC Adv., 2020, 10, 1249-1260 This journal is

Phosphate Recovery by a Surface-Immobilized Cerium Affinity Peptide

“…Moreover, this behavior provides the potential to improve surface functional sites of the peptide–cerium adsorbent under high-pH condition treatments, showing the ability to further enhance phosphate adsorption. Overall, our results corroborate the findings that pH is a critical parameter affecting the adsorption mechanisms of phosphate aqueous solutions and are similar to those of previous studies, in which the maximum adsorption capacity for cerium materials is under acidic to neutral conditions. ,,, …”

“…Overall, our results corroborate the findings that pH is a critical parameter affecting the adsorption mechanisms of phosphate aqueous solutions and are similar to those of previous studies, in which the maximum adsorption capacity for cerium materials is under acidic to neutral conditions. 15,16,18,40 Influence of Competing Ions on the Assembled Peptide−Cerium Films. Selectivity is an important factor for metal-based adsorbent design when considering use in a complicated wastewater environment.…”

“…This observation matched our previous pH effect results and is supported by other studies, as well, which have observed a higher level of phosphate binding under acidic conditions. 13,16,18,48 Control experiments with synthetic wastewater (pH 7) exposed to bare gold-coated crystal sensors and exposed to the peptide without cerium can be found in Figure S9. Generally, no strongly bound materials remained after a DI water rinse on bare gold or on peptide films without cerium.…”

“…11 The use of bio-derived supports for cerium-based phosphate adsorbents is becoming a promising, cost-effective approach to materials design. For instance, fibrous proteins, 16 chitosan, 17 and aminated lignin 18 have been utilized as supports for cerium-based phosphate recovery. However, like non-bio-derived options, it is difficult to tailor the structural and chemical properties of the composite materials, which represents a major challenge.…”

Multifunctional lignin-based nanocomposites and nanohybrids

“…For instance, Liu et al functionalized cerium oxide (Ce 2 O) NPs with aminated lignin through an in situ precipitation approach to obtain materials for wastewater treatment. 308 The prepared nanohybrids showed a diameter of 15 nm and a BET surface area of 90 m 2 g −1 , providing a 14-fold increase in phosphate adsorption capacity in comparison with bare lignin. Moreover, the inherent adsorbent capacity of Ce 2 O towards phosphate was upgraded using lignin as a support material, which avoids NP agglomeration and provides functional groups for the complexation between the Ce–OH of the nanohybrids and phosphate via Ce–O–P coordination bonds.…”